CN110156949B - Process for preparing polymer polyol dispersions and use of stabilizers therein - Google Patents

Abstract

The present invention relates to a process for preparing polymer polyol dispersions and to the use of a stabilizer (S) for stabilizing polymer polyol dispersions.

Description

Process for preparing polymer polyol dispersions and use of stabilizers therein

This application is a divisional application of the invention patent application PCT/EP2015/059148 entitled "stabilizer for polymer polyol preparation" filed on 28.4.2015, originally filed on 28.10.2016 into the chinese country and filed on 28.10.2016, and chinese patent application No. 201580023607.4 was obtained.

Technical Field

The invention relates to a stabilizer for a polymer polyol preparation method, and preparation and application thereof.

In particular, the stabilizers of the present invention are suitable for stabilizing polymer polyol dispersions prepared by melt emulsification (melt emulsification).

Background

In this context, the term "melt emulsification" refers to a process that involves only physical mixing of the components, and does not involve chemical reactions.

In WO2009/155427, the term melt emulsification is defined as follows:

another way to disperse the preformed polymer is to melt it and then blend the molten polymer with the polyol under shear. The shearing action breaks the molten polymer into small droplets that are dispersed in the polyol phase. This process is described in U.S. patent No. 6,623,827. This patent describes a process wherein a preformed polymer is melted in an extruder, mixed with a surfactant and a polyether polyol, and subsequently mixed with more polyether polyol. The mixture is then allowed to cool to solidify the particles.

The term stabilizer may be defined as a compound obtained by: macromers (macromers) having reactive unsaturation are reacted with styrene and acrylonitrile in a polyether polyol, optionally with a chain transfer agent. The stabilizers of the present invention are used for the preparation of polymer polyols containing small particles with a D50 of less than 25 μm, preferably less than 10 μm, most preferably less than 5 μm, by melt emulsification and should be able to stabilize polymer polyol dispersions for a longer period of time (prevent phase separation).

Stabilization was determined by storing the samples for an extended period of time and visually observing them before and after the typical six month storage period. If no precipitate forms at the bottom of the sample container (i.e., no phase separation), the sample is considered stable and thus the stabilizer is considered to be functional.

In essence, the stabilizers of the present invention are different from the stabilizers described in EO1675885, US6013731, 5990185 or EP0786480, which are preformed by free radical polymerization for standard grafting processes. The requirements and challenges for a process for forming and stabilizing polymer polyol dispersions by free radical polymerization are fundamentally different.

EP 1506240A 0 discloses graft polyols prepared by a continuous process. This process is a standard process for obtaining a final polymer polyol product using free radical polymerization. Thus, the stabilizers of EP 1506240 a0 are different from the stabilizers used in the melt emulsion process, since the process is not a melt emulsion process. Poor performance (inefficient phase stabilization) results from the use of small amounts of macromer (16% based on TMI and polyether polyol).

WO2012154393 describes polymer stabilizers prepared by copolymerizing unsaturated polyethers with low molecular weight monomers in a controlled radical polymerization. The polymer stabilizer is used to prepare a polymer polyol product by a mechanical dispersion process or an in situ polymerization process. The stabilizers obtained by radical polymerization have a greater variability in their structure than those obtained by controlled radical polymerization. Stabilizers prepared by free radical polymerization and controlled radical polymerization are fundamentally different. The molecular weight distribution, by-products, molecular weight, etc. are very different. Even products with similar compositions obtained by both methods are not comparable.

In contrast to WO2012154393, the present invention describes, among other things, the synthesis of stabilizers by radical polymerization of macromers for radical polymerization. The product is used in a melt emulsification process to obtain a polymer polyol product containing styrene-acrylonitrile copolymer as the dispersed phase.

One aspect of the present invention is the synthesis of a stabilizer that effectively stabilizes a dispersion of styrene-acrylonitrile copolymer in a polyether phase. It can be shown that the dispersions obtained with these stabilizers obtained by this process have a small particle size and have an improved long-term stability.

It can be shown that the composition of the stabilizers of the invention is important for the stabilization. Surprisingly, the ratio between the monomers styrene and acrylonitrile does not have to be matched to the ratio of the SAN materials used to obtain a stable dispersion.

Disclosure of Invention

The object of the present invention is therefore a stabilizer (S), preferably for use in a melt emulsification process for the preparation of polymer polyols, comprising from 10 to 70 wt. -%, preferably from 30 to 60 wt. -%, more preferably from 40 to 55 wt. -%, based on the sum of all components, of at least one polyol P2 comprising the reaction product of at least one macromer M, styrene and acrylonitrile in P2, optionally with an initiator and/or a chain transfer agent, and at least one polyol CSP, wherein the content of macromer M of the stabilizer (S) is from 30 to 70 wt. -%, preferably from 35 to 54 wt. -%, based on the sum of all components, and/or wherein the polyol CSP is preferably of comb structure.

In the present disclosure, the term "stabilizer" (S) refers in a general sense to a chemical compound.

The stabilizer (S) is a compound which is believed to stabilize the styrene-acrylonitrile copolymer dispersion in the polyether phase and thus is believed to stabilize the polymer polyol dispersion. In particular, the stabilizer (S) is believed to stabilize the polymer polyol dispersion obtained by the melt emulsification process.

Further objects of the present invention are also a process for preparing the stabilizers (S) according to the invention by free-radical polymerization of styrene, acrylonitrile and at least one macromer M in the presence of at least one polyol P2, and also a process for preparing polymer polyol dispersions by melt emulsification, in which the stabilizers (S) according to the invention are used.

The polyol P2 is generally selected from polyether Polyols (PEOL), preferably from PEOL having a molecular weight Mn of 1000g/mol to 6000g/mol, more preferably from PEOL having a molecular weight of 2000g/mol to 5000 g/mol. Mn can be determined as follows.

WO 2002/28937 describes stabilizers for use in stable dispersions for PU applications. These stabilizers are described as preferably substantially free of functional groups. In contrast to this disclosure, the stabilizers of the invention described herein contain OH functional groups which, by interacting with the carrier polyol used, can improve the storage stability of the resulting dispersions. In addition, the OH functions of the stabilizers interact with the isocyanates during the PU reaction and lead to an improved embedding of the SAN particles in the PU matrix.

As mentioned above, in a preferred embodiment, the polyol CSP comprised in the stabilizer of the invention is of comb-like structure.

In this preferred comb structure, the conventional distance between the two macromonomers is from 16 styrene and acrylonitrile units up to 500 styrene and acrylonitrile units, preferably from 30 styrene and acrylonitrile units up to 200 styrene and acrylonitrile units.

Drawings

Fig. 1 shows an exemplary embodiment of a comb-structured polyol CSP (21), which comb-structured polyol CSP (21) is a component of a preferred embodiment of the stabilizer (S) of the present invention, wherein (22) refers to a copolymer chain composed of styrene and acrylonitrile, and (23) represents a macromonomer unit.

Detailed Description

EP 1675885 gives a definition of the term preformed stabilizer:

the preformed stabilizer (PFS) is particularly useful for preparing polymer polyols having lower viscosities at high solids contents. In the preformed stabilizer process, a macromer is reacted with a monomer to form a copolymer of macromer and monomer. These copolymers comprising macromers and monomers are generally referred to as preformed stabilizers (PFS). The reaction conditions may be controlled such that a portion of the copolymer precipitates from solution to form a solid. In many applications, dispersions having a low solids content (e.g., 3 to 15% by weight) are obtained. Preferably, the reaction conditions are controlled so that the particle size is small, thereby enabling the particles to act as "seeds" in the polymer polyol reaction.

For example, U.S. Pat. No. 5,196,476 discloses a preformed stabilizer composition prepared by polymerizing a macromer with one or more ethylenically unsaturated monomers in the presence of a free radical polymerization initiator and a liquid diluent in which the preformed stabilizer is substantially insoluble. EP0,786,480 discloses a process for preparing a preformed stabilizer by polymerizing 5 to 40% by weight of one or more ethylenically unsaturated monomers in the presence of a free radical initiator in the presence of a liquid polyol comprising at least 30% by weight (based on the total weight of the polyol) of a coupling polyol which may have induced unsaturation. These preformed stabilizers can be used to prepare polymer polyols that are stable and have a narrow particle size distribution. The coupling polyol is necessary to achieve a small particle size (preferably 0.1 to 0.7 microns) of the preformed stabilizer. U.S. Pat. Nos. 6,013,731 and 5,990,185 also disclose preformed stabilizer compositions comprising the reaction product of a polyol, a macromer, at least one ethylenically unsaturated monomer, and a free radical polymerization initiator.

Bulky molecules are known to be effective macromers because less material can be used to sterically stabilize particles. See, for example, EP 0786480. In general, this is because highly branched polymers have a significantly larger excluded volume than linear molecules (e.g., monohydric alcohols) and thus require less branched polymer. U.S. Pat. No. 5,196,476 discloses that functionalities of 2 and higher, preferably 3 and higher, are suitable for preparing macromers.

Macromers based on multifunctional polyols and having multiple reactive unsaturated sites are described in U.S. Pat. No. 5,196,476. As described in this document, there is an upper limit to the concentration of unsaturation when making macromers via the maleic anhydride route. If the molar proportion of unsaturation per mole of polyol is too high, species having more than one double bond per molecule are more likely to form. Generally, the' 476 patent employs from about 0.5 moles to about 1.5 moles, preferably from about 0.7 moles to about 1.1 moles, of reactive unsaturated compound per mole of alkoxylated polyol adduct.

As mentioned above, preformed stabilizers (PFS) are known in principle in the art for the process of forming dispersions by free-radical polymerization. However, the requirements for the stabilizers to be used in the melt emulsification process are different (even though the preparation of the stabilizers may be similar).

Melt emulsification methods involve only physical mixing of the components and do not involve chemical reactions. In the conventional process (free radical polymerization), the PFS or macromer is added during the free radical polymerization. Thus, the residence time is different and there is no post-polymerization or additional polymer chain growth in the melt emulsification process.

Further, it is considered that the stabilizer of the present invention preferably contains a comb-like structured polyol CSP. These polyol CSPs are believed to have a backbone formed of styrene/acrylonitrile (SAN) polymers that interact with the SAN contained in the polymer polyol product to be stabilized. Furthermore, the macromers used in the synthesis of the stabilizers of the present invention generally have functional groups which are believed to interact with the polyol of the polymer polyol product to be stabilized and which are reactive with isocyanates during the PU reaction. The method improves the incorporation of the grafted particles in the PU network.

The stabilizers of the invention generally have a viscosity of from 1000 to 100000mPas, preferably from 5000 to 80000mPas, more preferably from 8000 to 60000mPas, at 25 ℃.

The OH number of the stabilizers of the invention is generally from 1mg KOH/g to 100mg KOH/g, preferably from 1mg KOH/g to 50mg KOH/g, more preferably from 10mg KOH/g to 40mg KOH/g.

The hydroxyl number was determined in accordance with DIN 53240(DIN ═ Deutsche industrinorm, german industry standard) from 2012.

Unless otherwise indicated, the viscosity of the polyols was determined at 25 ℃ by means of a Rheotec RC20 rotational viscometer using a CC 25DIN spindle (rotor diameter: 12.5 mm; measuring cylinder internal diameter: 13.56mm) according to DIN EN ISO3219 of 1994, all at a shear rate of 100/1s (but not 50/1 s).

In a preferred embodiment of the stabilizer of the invention, the ratio of styrene to acrylonitrile is greater than 1:1, preferably greater than 1:1.5, most preferably greater than 1: 2.

The synthesis of the stabilizers (S) of the invention described herein is generally carried out by free-radical polymerization of a macromer or macromer mixture with styrene and acrylonitrile in a carrier polyol (P2) in the presence of a free-radical initiator and optionally a chain transfer agent. The reaction is generally carried out in a semi-batch process; but may be a batch process or a continuous process. The monomer, macromer or mixture of macromers, carrier polyol, initiator, or chain transfer agent can be added to the reactor continuously or stepwise before, during, or after the reaction.

Different free radical initiators may be used, for example azo derivatives such as AIBN, peroxides such as t-amyl peroxide, hydroperoxides and percarbonates. Most preferred are azo derivatives, in particular AIBN (azoisobutyronitrile) and/or dimethyl 2,2' -azobis (2-methylpropionate).

The stabilizers of the present invention are useful for stabilizing polymer polyol dispersions, particularly polymer polyol dispersions prepared by melt emulsification.

In a preferred embodiment, when using the stabilizers of the invention, the resulting polymer polyol dispersions have a solids content of from 10% to 50%, preferably from 30% to 46%, and a viscosity at 25 ℃ and a shear rate of 1001/s of from 1000 to 20000mPas, preferably from 3000 to 15000mPas, more preferably from 5000 to 12000 mPas.

In order to measure the solid content, a polymer polyol sample is added into a centrifugal tube, diluted by a solvent in the centrifugal tube and fully shaken up; centrifuging the mixture with a high speed centrifuge and removing the supernatant from the centrifuge tube by pouring; repeating the whole process at least twice, and then placing the centrifuge tube containing the sample in a vacuum furnace for drying; after cooling to room temperature, the solids remaining in the centrifuge tube were weighed to calculate the solids content in the sample.

The particle size D50 of the stabiliser according to the invention is preferably less than 0.5 μm, more preferably less than 0.3 μm (determined by static laser diffraction using a Mastersizer 2000(Malvern Instruments Ltd.) after dilution of the sample with isopropanol to give an optical concentration suitable for measurement the calculation of the particle size distribution of the Hydro SM. using a 2500rpm stirring rate for the dispersion of the sample can be carried out by the Mastersizer 2000 using Fraunhofer theory).

And (3) synthesis of a macromonomer:

macromonomers are defined as molecules containing one or more polymerizable double bonds capable of copolymerizing with vinyl monomers such as styrene and acrylonitrile, and containing one or more hydroxyl terminated polyether chains. Conventional macromers include polyether polyols having unsaturated groups, which are typically prepared by reacting a standard polyether polyol with an organic compound containing an unsaturated group and a carboxyl, anhydride, isocyanate, epoxy or other functional group capable of reacting with an active hydrogen-containing group. Useful isocyanates include isocyanatoethylmethyl acrylate (IEM) and 1, 1-dimethyl meta-isopropenyl benzyl isocyanate (TMI).

In a preferred embodiment of the present invention, TMI is used to prepare the macromer. Typically, the macromer is synthesized in the presence of a Lewis acid catalyst.

Suitable Lewis acid catalysts typically include tin-based, boron-based, aluminum-based, gallium-based, rare earth-based, zinc-based, or titanium-based compounds. Representative tin-based compounds include: dibutyltin diacetate, dibutyltin dibromide, dibutyltin dichloride, dibutyltin dilaurate, dibutyltin dimethoxide, dibutyltin oxide, dimethyltin diacetate, dimethyltin dibromide, diphenyltin dichloride, diphenyltin oxide, methyltin trichloride, phenyltin trichloride, tin (IV) acetate, tin (IV) bromide, tin (IV) chloride, tin (IV) iodide, tin (II) oxide, tin (II) acetate, tin (II) bromide, tin (II) chloride, tin (II) iodide and tin (II) 2-ethylhexanoate (stannous octoate). Representative boron-based compounds include: boron tribromide, boron trichloride, boron trifluoride, and tris (pentafluorophenyl) borane. Representative aluminum-based compounds include: aluminum chloride and aluminum bromide. Representative gallium-based compounds include: gallium chloride, gallium bromide, and gallium (III) acetylacetonate.

Representative rare earth catalysts are typically salts of scandium, yttrium, lanthanum, praseodymium, neodymium, erbium, thulium, ytterbium, neodymium, or lutetium. Examples include: ytterbium triflate, ytterbium (III) acetylacetonate, erbium (III) triflate (erbium triflate), erbium (III) acetylacetonate, holmium triflate, terbium triflate, europium (III) trifluoroacetate, samarium triflate, neodymium (III) acetylacetonate, praseodymium triflate, lanthanum triflate, and dysprosium triflate. Representative zinc-based compounds include zinc chloride and zinc bromide. Representative titanium compounds include titanium bromide (iv) and titanium chloride (iv).

Various methods are known in the art for introducing reactive unsaturation into polyols. The synthesis of useful macromers is described in WO 2005/003200. Macromer A is the product obtained by the reaction of a trifunctional polyether polyol with 1, 1-dimethyl m-isopropenyl benzyl isocyanate (TMI). Macromer B is the product obtained by the reaction of a hexafunctional polyether polyol with 1, 1-dimethyl m-isopropenyl benzyl isocyanate (TMI).

The molecular weight of the polyol can generally be calculated by the following formula: mn ═ f × 56100/OH value, where Mn ═ number average molecular weight in g/mol; (ii) the functionality, number of OH groups per molecule, determined by the starting materials used to synthesize the macromonomer; OH number-the number of hydroxyl groups of the oligomeric polyol, in mg KOH/g.

Polymer polyol dispersions stabilized with at least one stabilizer of the invention can be used for preparing Polyurethanes (PU).

Generally, in the preparation of polyurethanes, at least one polyol is reacted with at least one polyisocyanate or isocyanate, optionally in the presence of at least one blowing agent and/or catalyst.

In this PU production process, the conventional a-component consists of one or more polyols, one or more polyurethane catalysts, one or more surfactants, one or more crosslinkers, water, or optionally other chemical or physical blowing agents. The B component generally contains isocyanate.

In another embodiment of the present invention, in the PU preparation process, polymer polyols comprising the stabilizers of the present invention may also be used to obtain a stable A-component, so that the A-component can be stored for longer periods of time without phase separation.

Example (b):

in the following section, some experimental examples are given to illustrate some aspects of the present invention.

General procedure for the synthesis of stabilizers:

the glass reactor is loaded with the carrier polyol, optionally (i.e., initially) the macromer or macromer mixture, optionally acrylonitrile, optionally styrene, optionally a chain transfer agent, and heated to 125 ℃. The mixture of carrier polyol, initiator, styrene, acrylonitrile, and macromer or macromer mixture was added over 100 minutes. The reaction mixture was stirred at 125 ℃ for a further 20 minutes. The mixture was then evacuated under reduced pressure at 125 ℃ for 120 minutes to remove residual monomer. The obtained stabilizer was characterized and used without further purification.

The composition of a representative stabilizer obtained by this method is shown in table x. All amounts are in weight%. All experiments were carried out using 0.5 wt% azo initiator (dimethyl 2,2' -azobis (2-methylpropionate) and 0.4% thiol-containing chain transfer agent the weight percentages given in this section refer to the final product (i.e. the stabilizer).

TABLE 1

The remainder (the remainder when totaling 100% by weight) consists of initiator(s) and chain transfer agent(s).

Preparation of polyol dispersion:

the following dispersions were obtained by using commercially available styrene-acrylonitrile copolymer types with different styrene and acrylonitrile compositions. For example, those available from Samsung

Type, available from Styrolysis

Type, available from Ineos

Type (b). A round bottom flask equipped with a stirrer and a nitrogen inlet was filled200g of SAN of the type indicated in Table x and 50g of the selected stabilizer were charged and heated to 245 ℃ under a nitrogen atmosphere. The mixture was stirred at this temperature for 15 minutes. Will be provided with

2095 are heated to 245 deg.C and added with vigorous stirring. After addition the mixture was stirred for an additional 30 minutes and then cooled to RT. Particle size was determined by light scattering, as previously described. The particle size is used as an indicator of the efficiency of the stabilizer system.

In contrast to example 4, examples 1 to 3 show that the ratio between styrene, acrylonitrile, macromer or macromer mixture and carrier polyol used for the synthesis of the stabilizer is important for effective stabilization of the dispersions prepared. Stabilizer 3 used in example 4 shows that the use of large amounts of styrene and acrylonitrile for the preparation of the stabilizer leads to inefficient stability of the dispersions obtained with these products. Example 5 using stabilizer 4 and example 8 using stabilizer 7 show that the amount of macromer used is critical to obtain an effective stabilizer system.

The ratio between the monomers styrene and acrylonitrile used to prepare the stabilizer does not have to be matched to the ratio of SAN material used to obtain a stable dispersion. The styrene to acrylonitrile ratio of the stabilizer used in examples 2 and 7 was 1.86 to 1 and the composition of the SAN used as the dispersed phase was 3.16 to 1. In both cases, very stable dispersions with small particle size can be obtained. Stabilizer 6 cannot be used to prepare the dispersion because of the high viscosity of the stabilizer. These highly viscous stabilizers cannot be handled under normal conditions.

Claims (21)

1. Process for preparing a polymer polyol dispersion by melt emulsification, wherein a stabilizer (S) is used which comprises from 32 to 55% by weight, based on the sum of all components, of at least one polyol P2, and at least one polyol CSP comprising the reaction product of at least one macromer M, styrene and acrylonitrile in P2, optionally with an initiator and/or a chain transfer agent, wherein the content of macromer M of the stabilizer (S) is from 35 to 54% by weight, based on the sum of all components, wherein the total content of styrene of the stabilizer (S) is from 4 to 15% by weight, based on the sum of all components, and the total content of acrylonitrile of the stabilizer (S) is from 2 to 7% by weight, based on the sum of all components, and wherein the macromer M passes, optionally in the presence of a Lewis acid catalyst, 1-dimethyl m-isopropenyl benzyl isocyanate (TMI) and a polyether polyol PM.

2. The method of claim 1, wherein the polyol CSP is a comb structure.

3. The process according to claim 1 or 2, wherein the stabilizer (S) consists of one or two polyols P2 and one or two polyols CSP comprising the reaction product of at least one macromer M, styrene and acrylonitrile in P2 optionally with an initiator selected from azo initiators and peroxide initiators and/or a chain transfer agent selected from dodecyl mercaptan, isopropyl alcohol and 2-butanol.

4. The process according to claim 1 or 2, wherein the stabilizer (S) consists of one or two polyols P2, one or two polyols CSP consisting of the reaction product of macromer M, styrene and acrylonitrile in P2.

5. The process according to claim 1 or 2, wherein the macromonomer M has an average molecular weight Mn of from 1000g/mol to 50000 g/mol.

6. The process according to claim 1 or 2, wherein the macromonomer M has an average molecular weight Mn of 2000g/mol to 30000 g/mol.

7. The process according to claim 1 or 2, wherein the macromonomer M has an average molecular weight Mn of from 3000g/mol to 20,000 g/mol.

8. The process of claim 1 or 2 wherein the macromonomer M has an average of from 0.2 to 1.2 polymerizable ethylenically unsaturated groups per molecule, and/or from 2 to 8 hydroxyl groups per molecule.

9. The process according to claim 1 or 2, wherein the polyether polyol PM used in the preparation of the macromer M is selected from trifunctional polyether polyols and hexafunctional polyether polyols.

10. The process of claim 1 or 2, wherein the ratio of styrene to acrylonitrile is greater than 1:1.

11. The process of claim 1 or 2, wherein the ratio of styrene to acrylonitrile is greater than 1: 1.5.

12. The process of claim 1 or 2, wherein the ratio of styrene to acrylonitrile is greater than 1: 2.

13. The process of claim 1 or 2, wherein the viscosity of the stabilizer is from 1000 mPa-s to 100000 mPa-s, determined at 25 ℃ according to DIN EN ISO3219 and a shear rate of 1001/s.

14. The process of claim 1 or 2, the stabilizer having a viscosity of from 5000mPas to 80000mPas, determined at 25 ℃ according to DIN ENISO3219 and a shear rate of 1001/s.

15. The process of claim 1 or 2, wherein no additional solvent is used.

16. The process of claim 1 or 2, wherein the polymer polyol dispersion obtained has a solids content of from 10% to 50% and/or a viscosity at 25 ℃ of from 1000 mPa-s to 20000 mPa-s and/or an average particle size of D50<50 μm.

17. The process of claim 1 or 2, wherein the polymer polyol dispersion obtained has a solids content of from 30% to 46%.

18. The process according to claim 1 or 2, wherein the polymer polyol dispersion obtained has a viscosity at 25 ℃ of from 3000 mPa-s to 15000 mPa-s.

19. The process of claim 1 or 2, wherein the polymer polyol dispersion obtained has a viscosity at 25 ℃ of from 5000 mPa-s to 12000 mPa-s.

20. Use of a polymer polyol obtained by the process of claim 1 or 2 for the preparation of polyurethanes.

21. Use of a stabilizer (S) for stabilizing a polymer polyol dispersion prepared by melt emulsification, wherein the stabilizer (S) comprises 32 to 55 wt.%, based on the sum of all components, of at least one polyol P2, and at least one polyol CSP comprising the reaction product of at least one macromer M, styrene and acrylonitrile in P2, optionally with an initiator and/or a chain transfer agent, wherein the content of macromer M of the stabilizer (S) is from 35 to 54 wt.%, based on the sum of all components, wherein the total content of styrene of the stabilizer (S) is from 4 to 15 wt.%, based on the sum of all components, and the total content of acrylonitrile of the stabilizer (S) is from 2 to 7 wt.%, based on the sum of all components, and wherein the macromer M passes, optionally in the presence of a Lewis acid catalyst, 1-dimethyl m-isopropenyl benzyl isocyanate (TMI) and a polyether polyol PM.

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